A Recipe from Sneaky Kitchen
Yam & Plantain Fufú

2 to 3 Tablespoons olive oil  
1 medium onion, chopped 
1 large sweet potato or yam, in 1/2" cubes
1/2 cup white cooking wine 
1 large completely ripe plantain, in 1/2" cubes  
1/2 teaspoon salt
1/4 teaspoon black pepper
red pepper flakes (optional- only if you like everything hot)

Heat olive oil in a non-stick skillet or wok.  Add chopped onion and sauté briefly.  Add sweet potato and sauté, stirring from time to time, until onion is soft.  Add liquid, turn low and simmer for five minutes.  

Add plantains, salt & pepper (and red pepper flakes if you are using them).  Stir to mix, cover and continue to simmer only until sweet potatoes are cooked through. 

Uncover and increase heat, stirring occasionally.  When liquid is gone, continue to sauté, turning frequently with a spatula (not stirring), until nicely browned.  Serve hot.